AOA Wind Tunnel Demonstration

The significance of angle of attack upon swept wing airfoils has been known for decades, as illustrated by a 1957 video from the National Advisory Committee for Aeronautics -- NASA's predecessor organization.

Watch the movement of the tufts of cloth fixed to the 40 degree swept wing. As the angle of attack increases steadily from 12.7 degrees, the tufts rise, indicating airflow separation and consequent loss of lift, beginning near the tips and progressing inward. These tests were conducted in the full-scale wind tunnel at the Langley Research Center in Virginia.